How climate change could change Acadia over the next 100 years

Editor’s Note: This is part one of a three part series looking at the next 100 years of Acadia National Park. Be sure to watch for part two!

Bass Harbor Head Lighthouse. Micky Bedell | BDN

This summer, Acadia National Park turns 100. Born on July 8, 1916, when President Woodrow Wilson forever safeguarded 5,000 acres on Mount Desert Island, the park has evolved from a getaway for the wealthy to arguably Maine’s most precious natural resource.

While great fanfare will accompany its centennial celebration, a century is but a blink of an eye for the park, long ago scoured and sculpted into Maine granite by the force of glaciers.

Today, the pressures exerted on the park are manmade. Acadia, established under the tenets of preservation, must now contend with the realities of change.

At sea, climate upheaval could lead to rising tides and more violent storms that threaten to remake the park’s signature craggy coastline. Cruise ships are docking in nearby Bar Harbor in record numbers, buoying a regional economy that clings to its small-town appeal.

On land, those who live and work in the park’s shadow both depend on and lament its popularity. Acadia now draws more people each year than reside in the entire state, apparent in the choking summertime traffic that clogs its gates. Park officials strive to welcome scores of visitors who endanger Acadia’s largely pristine scenery with their very presence.

But those who value the park will ensure its protection long into the future. This summer, some will meet Acadia for the first time, perhaps over a meal of popovers and chowder on the lawn at Jordan Pond House. Others will sink their toes into the sand at Echo Lake and remember with fondness their childhood vacations. A few may gaze into the clear night sky from the peak of Cadillac Mountain and wonder what’s written in the stars for one of Maine’s most treasured and iconic landscapes.

Join us as we explore the outlook for Acadia’s next 100 years.

Stewards of the environment

Between blocks of pink granite, vehicles and bicyclists slowly climb the winding road to the top of Cadillac Mountain. The ocean sparkles below, and overhead not a cloud floats in the pale blue sky. It is mid-May, and tourists are just starting to filter into Acadia National Park.

Near the summit of the mountain, within sight of the road, two botanists crouch by a raised bed garden filled with native plants. Inspecting leaves and blossoms, they scribble on waterproof notebooks as black flies swarm around their heads.

The experimental garden — the first of its kind in Acadia — is helping researchers understand which of the park’s native plants will adapt to warming temperatures due to climate change.

Many have already succumbed. Acadia has lost about 20 percent of the plant species that existed in the park a century ago.

“When you look at the park — if you’re a visitor or you’re looking at a photo — it’s hard tell the changes that have happened,” said Abe Miller-Rushing, Acadia’s science coordinator. “We still have plants. We still have a lot of plants. You’re going to come and see lots of green, but you won’t necessarily see that one of every five plant species is gone.”

Botanist Caitlin McDonough MacKenzie is studying the leaf out and flowering of plants that have been transplanted to lower elevations of Cadillac Mountain to see how they will respond to future climate change. Linda Coan O’Kresik | BDN

Sheep laurel is one of the plants that botanist Caitlin McDonough MacKenzie is studying at different elevations of Cadillac Mountain to see how it will respond to future climate change. Linda Coan O’Kresik | BDN

This experimental garden on Cadillac Mountain is the first of its kind in Acadia National Park. Linda Coan O’Kresik | BDN

The information gleaned from the experimental garden will be used to restore vegetation on the park’s mountains, including Cadillac, a major destination for visitors.

“It’s totally a new thing [for the park], to be thinking about what it means to manage change,” Miller-Rushing said. “If you’re trying to keep ecosystem processes functioning, maintain ecological integrity, what does that look like?”

“We know, for instance, in the next 75 years, a lot of the spruce fir and conifer forest will change to being mostly hardwood,” he added. “And you know, how do you manage for that? We can’t fight against it.”

On the mountains of the park, the temperature tends to drop as elevation increases. Therefore, for experimental gardens on Cadillac, researchers simply transplanted plants from the summit to lower, warmer elevations to simulate warming temperatures from climate change.

A marker denotes one of the plants being studied in an experimental garden on Cadillac Mountain. Linda Coan O’Kresik | BDN

Planted in fall 2013, there are three experimental gardens on Cadillac: at the summit, halfway down, and at its base. The project’s leader, Caitlin McDonough MacKenzie, selected three native species to for the experiment: lowbush blueberry, three-toothed cinquefoil and sheep laurel. All three are common throughout the park at all elevations.

“Our three species here have actually done a really nice job,” said MacKenzie. “They’ve responded pretty flexibly to that change in temperature, which gives us hope they’ll be able to adapt to warmer temperatures at the summit in the future.”

In addition to those higher temperatures, climate scientists are also predicting longer growing seasons, rising sea levels and increased storm surges for Acadia National Park.

“We’re going to have to be more proactive in terms of the management of the park because things are changing, and if we keep the status quo, they’re likely to change in ways we don’t want,” said Miller-Rushing said.

Before looking forward, however, park officials looked back to a record and tradition of scientific research in Acadia that began before the park was even established.

The park has been affected by climate change and other stressors since its inception 100 years ago, which is known because of extensive monitoring of natural resources in the park, as well as research by scientists from numerous institutions and organizations.

In 1880, when MDI was becoming a popular spot for adventurous summer rusticators, a group of young men from Harvard sailed to the island to spend the summer camping and exploring the natural landscape. The called themselves the “Champlain Society.”

Led by young Charles Eliot, son of Harvard President Charles W. Eliot, the Champlain Society spent several summers on the island, camping in tents by the ocean. And under orders to do something useful with their time, they studied the island’s plants, wildlife, geology, hydrology and meteorology, conducting the first natural history surveys of MDI.

Among those surveys was the first complete plant inventory of the island, published in 1894 as “Flora of Mount Desert Island, Maine.”

Another well documented change is the length of the island’s growing season. Relative to 50 years ago, spring (last frost) starts three weeks earlier, while fall (first frost) starts three to four weeks later.

Other documented changes on the island include more intense rain events, different bird species and ocean acidification.

“Clearly things are changing,” Miller-Rushing said. “If we were ever supposed to be keeping things the same, we haven’t been doing a good job at it. We realize it’s an impossible task.”

To be fair, preventing change in Acadia has been an impossible task for a century. Just ask the summer rusticators, who tried to protect the park from a scourge as challenging to control as climate change: Traffic.

Cars and pedestrians crowd the parking lot at the summit of Cadillac Mountain in Acadia National Park in this 2015 photo. Bill Trotter | BDN

Coming up next

With more visitors flocking to Acadia National Park each year than reside in the entire state of Maine, the surge in visitation has brought so many tourist dollars into the local economy. But it’s also brought traffic, congestion and a growing need for new construction. What will happen to Acadia and the surrounding towns in the future? Can it even handle any more tourism?